The eating disorders, Anorexia Nervosa and Bulimia Nervosa, are psychiatric illnesses of uncertain etiology which affect a significant number of women and which are associated with substantial morbidity and mortality. A central behavioral feature of these disorders is a disturbance in the control of meal size. Anorexia Nervosa is characterized by abnormally small meals and Bulimia Nervosa by abnormally large ("binge") meals. Substantial progress has been made in the last two decades in understanding the controls of meal size in laboratory animals, but direct applications of these models to disordered eating are lacking. A second clinical characteristic of eating disorders is a narrowing of behavioral repertoire so that food-related thinking and behavior progressively interfere with other occupational and social activities. This pattern is reminiscent of the behavior of individuals dependent on drugs. There are substantial preclinical data documenting the behavioral and neurochemical effects of drugs of abuse, but, again, there have been few attempts to examine systematically the utility of this information in understanding eating disorders. This proposed R21 Developmental Grant will translate preclinical knowledge of the controls of eating behavior and of substance use to the study of human eating disorders. A formal collaboration will be established between investigators with expertise in the study of feeding behavior in animals, investigators with expertise in the study of human substance abuse and investigators with expertise in the study of human eating and eating disorders. This research group will develop and conduct experiments to translate basic animal research into the study of human eating disorders and, conversely, to examine in animal models phenomena described in clinical experience with patients with eating disorders.